Informatica Testing Interview Questions and Answers
1. What is Performance tuning in Informatica?
ANS: The goal of performance tuning is optimize session performance so sessions run during the available load window for the Informatica Server. The performance of the Informatica Server is related to network connections.
2. How to increase the session performance?
ANS: Data generally moves across a network at less than 1 MB per second, whereas a local disk moves data five to twenty times faster. Thus network connections often affect on session performance. So avoid network connections.
Flat files: If your flat files stored on a machine other than the Informatca server, move those files to the machine that consists of Informatica server.
Relational datasources: Minimize the connections to sources, targets and Informatica server to improve session performance. Moving target database into server system may improve session performance.
3. How do you handle decimal places while importing a flatfile into informatica?
ANS: While importing flat file definition just specify the scale for a numeric data type in the mapping, the flat file source supports only number data type (no decimal and integer). In the SQ associated with that source will have a data type as decimal for that number port of the source.
Source ->number data type port ->SQ -> decimal datatype.Integer is not supported. hence decimal is taken care.
4. Differences between Normalizer and Normalizer transformation?
ANS: Normalizer: It is a transormation mainly using for cobol sources,
it change the rows into coloums and columns into rows
Normalization: To remove the redundancy and inconsistency
5. What is the target load order?
ANS: You specify the target load order based on source qualifiers in a maping. If you have the multiple source qualifiers connected to the multiple targets, you can designate the order in which Informatica server loads data into the targets.
6. How can you create or import flat file definition in to the warehouse designer?
ANS: You can not create or import flat file definition in to warehouse designer directly. Instead you must analyze the file in source analyzer, then drag it into the warehouse designer.
When you drag the flat file source definition into warehouse designer workspace, the warehouse designer creates a relational target definition not a file definition. If you want to load to a file, configure the session to write to a flat file. When the Informatica server runs the session, it creates and loads the flat file.
7. How do we do unit testing in Informatica?
ANS: Unit testing are of two types
1. Quantitative testing 2.Qualitative testing
8. How do we load data in Informatica?
1. First validate the mapping
2. Create session on them applying and then run workflow.
Once the session is succeeded the right click on session and go for statistics tab.
There you can see how many number of source rows are applied and how many number of rows loaded in to targets and how many number of rows rejected. This is called Quantitative testing.
If once rows are successfully loaded then we will go for qualitative testing.
1. Take the DATM (DATM means where all business rules are mentioned to the corresponding source columns) and check whether the data is loaded according to the DATM in to target table. If any data is not loaded according to the DATM then go and check in the code and rectify it.
This is called Qualitative testing.
This is what a developer will do in Unit Testing.
9. What is Data driven?
ANS: The Informatica server follows instructions coded into update strategy transformations with in the session mapping determine how to flag records for insert, update, delete or reject. If you do not choose data driven option setting, the Informatica server ignores all update strategy transformations in the mapping.
If the data driven option is selected in the session properties, it follows the instructions in the update strategy transformation in the mapping now it follows instructions specified in the session.
10. How the Informatica server sorts the string values in Rank transformation?
ANS: When Informatica Server runs in UNICODE data movement mode, then it uses the sort order configured in session properties.
11. Define Informatica repository?
ANS: Informatica Repository: The Informatica repository is at the center of the Informatica suite. You create a set of metadata tables within the repository database that the Informatica application and tools access. The Informatica client and server access the repository to save and retrieve metadata.
12. How can we partition a session in Informatica?
ANS: Partitioning option optimizes parallel processing on multiprocessor hardware by providing a thread-based architecture and built-in data partitioning.
The Power Center Partitioning option enables hardware and applications to provide outstanding performance and jointly scale to handle large volumes of data and users.
13. In update strategy target table or flat file which gives more performance? Why?
ANS: Pros: Loading, Sorting, Merging operations will be faster as there is no index concept and Data will be in ASCII mode.
Cons: There is no concept of updating existing records in flat file.
As there is no indexes, while lookups speed will be lesser.
14. What is parameter file?
ANS: When you start a workflow, you can optionally enter the directory and name of a parameter file. The Informatica Server runs the workflow using the parameters in the file you specify.
15. What are variable ports and list two situations when they can be used?
ANS: We have mainly tree ports Inport, Outport, Variable port. Inport represents data is flowing into transformation. Outport is used when data is mapped to next transformation. Variable port is used when we mathematical calculations are required. If any addition i will be more than happy if you can share.
We can use variable ports to store values of previous records which is not otherwise possible in Informatica.
16. Can you start a session inside a batch individually?
ANS: We can start our required session only in case of sequential batch. In case of concurrent batch we cant do like this.
17. What are the types of lookup caches?
1) Static Cache
2) Dynamic Cache
3) Persistent Cache
4) Reusable Cache
5) Shared Cache
18. What are two types of processes that Informatica runs the session?
ANS: Load manager Process: Starts the session, creates the DTM process, and sends post-session email when the session completes. The DTM process. Creates threads to initialize the session, read, write, and transform data, and handle pre- and post-session operations.